To the European immigrant - that is, to the aliens who have been converted into Americans by the advantages of American life - the Promise of America has consisted largely in the opportunity which it offered of economic independence and prosperity.

It also influenced the later New Deal. Increasingly skeptical of the capacity of social welfare legislation to remedy social ills Croly argued that America's liberal promise could be redeemed only by syndicalist reforms involving workplace democracy. After returning to America Herbert Croly worked as an editor for an architectural magazine The Architectural Record from 1900 to 1906.

Croley was one of the founders of modern liberalism in the United States especially through his books essays and highly influential magazine founded in 1914 The New Republic. Increasingly skeptical of the capacity of social welfare legislation to remedy social ills Croly argued that America's liberal promise could be redeemed only by syndicalist reforms involving workplace democracy.